Magnetic stripe cards are used for storing various types of data in the magnetic stripe. They find applications in different areas including payment cards, gift cards, security access control systems, identification system and toys, among others. A magnetic stripe card includes a plastic or paper card that has an attached magnetic stripe. Data are encoded magnetically on the magnetic stripe by modifying the magnetism of iron based ferromagnetic particles that are embedded in the magnetic stripe. There are usually three tracks of data encoded onto the magnetic stripe. The data can be retrieved by using magnetic card readers.
A magnetic card reader includes a magnetic read head and an adjacent card gliding groove. The magnetic read head includes a magnetic sensor, which in one example is a magnetic coil. A magnetic stripe of a magnetic card reader is swiped through the groove and the swiping motion generates an analog magnetic signal that is picked up by the magnetic sensor of the adjacent magnetic read head. The analog magnetic signal contains the magnetically encoded data of the magnetic stripe. The strength of the analog magnetic signal with the magnetically encoded data is usually weak, therefore the magnetic read head and the magnetic stripe need to be in close contact in order to obtain a “good” signal read. In manually operated magnetic card readers, the card gliding groove includes two opposing walls and the magnetic read head is placed on one of the walls, so that when the magnetic stripe of the magnetic card is placed inside the groove, the magnetic stripe on the card and the magnetic read head are aligned in position. The magnetic read head is usually housed in a metal compartment that also contains all the electronics inside. In most cases, the magnetic stripe can be read from both directions, that is, the magnetic card can be swiped starting from either end of the groove.
A magnetic stripe card is inexpensive compared to other card technologies and is easy to program. However, magnetic stripe technology is also susceptible to misreads, card wear, and data corruption. Therefore, in some cases, the magnetic card reader may be unable to read a magnetic card swipe successfully. There are many possible causes for this effect including, card swipe speed and uniformity, card alignment, degradation of the magnetically encoded data, and magnetic read head failure, among others.
When a magnetic card read fails, the user usually has to retry the card swipe. However, without any error feedback, the user has no way of knowing why the previous swipe failed and how to correct it. Therefore, a magnetic card reader with feedback information will be very useful in improving the success rate of a magnetic card read after a card read failure.